Burnt Out, Foggy or Exhausted in the Morning?Understanding Your Cortisol Awakening Response (CAR)

If you’re waking up tired, struggling to focus, or feeling wired at night but drained during the day — you’re not alone.

Many people are told it’s “just stress.”

But at Thrive, we look a little deeper.

Because stress isn’t just something you feel — it’s something your body regulates.

And one of the most important ways it does this is through your Cortisol Awakening Response (CAR).

What Is the Cortisol Awakening Response?

Your body is designed to wake up with energy.

Within the first 30–60 minutes after waking, your body naturally produces a surge in cortisol — your primary stress hormone.

This is called the Cortisol Awakening Response

This rise is not a bad thing — it’s essential.

It helps you:

• Feel alert

• Get out of bed

• Think clearly

• Start your day

In fact, cortisol typically rises by around 50% after waking, acting like a built-in “mini stress test” for your body

Why This Matters

Your Cortisol Awakening Response reflects how well your body’s stress system — theHypothalamic–Pituitary–Adrenal axis — is functioning.

Even if your labs are “normal,” this response can still be disrupted.

And when it is, you feel it.

When the CAR Is Out of Balance

Low or Blunted Response

You may feel:

• Exhausted on waking

• Unmotivated

• Foggy or slow

This pattern is often seen in:

• Burnout

• Chronic fatigue

• Poor sleep

• Long-term stress

  
  

Elevated Response

You may feel:

• Anxious first thing in the morning

• “On edge” before the day begins

• Overwhelmed early in the day

This can be linked to:

• Ongoing stress

• Blood sugar instability

• Pain or inflammation

  
  

“Normal” But Not Functioning Well

Even if cortisol levels appear normal:

The pattern of your response may not be

And that can affect:

• Energy

• Mood

• Focus

• Sleep

Why This Often Gets Missed

Most standard tests measure cortisol at a single point in time.

But your body doesn’t work that way.

Your stress response is dynamic — and changes throughout the day.

Without measuring your Cortisol Awakening Response, we can miss key insights into how your body is actually functioning.

How We Assess It

At Thrive, we may use the DUTCH Test (DUTCH Plus)

This advanced test measures:

• Your Cortisol Awakening Response (waking, +30, +60 minutes)

• Your cortisol rhythm across the day

• Hormones like oestrogen, progesterone, testosterone

• Sleep-related markers like melatonin

It gives us a much more complete picture of your stress and hormone health

Stress, Cortisol & Sleep

Your stress hormones don’t just affect your mornings — they impact your nights too.

We often see:

• High cortisol at night → difficulty sleeping

• Low melatonin → poor sleep quality

• Hormonal imbalances → disrupted rest

This is why you can feel:

• Exhausted all day

• But unable to switch off at night

Why This Matters for Your Brain

Your brain is highly sensitive to stress.

When your Cortisol Awakening Response is out of sync, it can affect:

• Mental clarity

• Focus and productivity

• Mood and emotional resilience

• Energy levels

That “brain fog” you feel isn’t random — it’s your body struggling to regulate.

Do You Need This Test?

Not everyone does.

But it may help if:

• You feel tired despite normal blood tests

• You struggle to wake up

• You feel wired at night

• You’re dealing with burnout or chronic stress

What Happens Next?

We don’t treat “cortisol” in isolation.

We treat the system.

That might include:

• Sleep optimisation

• Nervous system support

• Nutrition and blood sugar balance

• Hormonal support

  
  

The Takeaway Your body is designed to wake up feeling energised, focused, and ready for the day.

If that’s not happening, your Cortisol Awakening Response may be part of the picture.

And understanding it can be the first step to:

Better energy - Clearer thinking - More restful sleep.